Tension reel for lighting fixtures



N. ROBBOY July 31, 1956 TENSION REEL FOR LIGHTING FIXTURES Filed April15, 1955 v 1 6 mm M m m V T N A MM m l, A NM United States PatentTENSION REEL FOR LIGHTING FIXTURES Nathan Robboy, Cleveland Heights,Ohio Application April 15, 1955, Serial No. 501,621

2 Claims. (Cl. 242-107) This invention relates to supports for lightingfixtures and particularly to a tension reel support.

Fixture supports affording vertical adjustment for lighting fixturescommonly use a reeled cable housed in an egg or ball shaped case whichis suspended. from the ceiling between the fixture and the ceilingcanopy. Such cases are unsightly and detract from the appearance of thefixture installation. Furthermore, such devices ordinarily use a pawltype positioning mechanism in holding the suspended fixture in position,such as employed in window shades. Unless carefully released, thereeling action of the operating spring or weight will jerk the fixtureupward out of the users hand with resultant jarring or damaging of thefixture and light bulb. In addition, the pawl action of the lockingmechanism means that the fixture can be located only at intervalsgoverned by the shape and size of the pawl and the spacing of itscooperating lock notches.

The primary object of this invention, therefore, is to provide a tensionreel for lighting fixtures whose controlling mechanism is housed withinthe ceiling canopy usually used with such fixture, entirely concealedtherein and unseen by the observer.

Another object is to provide a tension reel for lighting fixtures whichpermits the suspended fixture to be moved smoothly up or down at thetouch of a finger while holding the fixture at any desired positioninstantly upon release.

A further object is to provide a tension reel of the type stated that isan improvement over the Tension Reel For Lighting Fixtures invented byme and described in my copending application Serial No. 474,709 filed inthe United States Patent Office on December 13, 1954.

Still other objects are to provide a tension reel that is economical tomanufacture, simple to install, rugged and reliable in action andadapted to support fixtures of different weights.

These and other objects of the invention will become apparent from areading of the following specifications and claims, together with theaccompanying drawing, wherein:

Figure l is a front elevation of the tension reel that is the subject ofthis invention, showing it mounted in a ceiling canopy and supporting anelectric fixture therefrom in alternate raised and'lowered positions;

Figure 2 is a front elevation of the tension reel in its unmountedcondition;

Figure 3 is a side elevation of the same with portions broken away andin section; and

Figure 4 is an exploded view of the housing and drum assembly.

Referring more particularly to Figure 1, there is seen the tension reelassembly broadly indicated by reference numeral 10, mounted within aconventional ceiling canopy 11 and having an electric fixture 12suspended from the end of its supporting cable 41. Electric current iscarried to the fixture 12 through a coiled cord 14 which 341 The member13 is U-shape'd with two parallel top and bottom walls 17 and 16respectively joined through a first side wall 15, as is seen mostclearly in Figure 4. The top wall 17 has two spaced mounting slots 20 bymeans of which the housing is attached to theelectric outlet box in theceiling 44, through mounting. bolts not shown. Referencenumeral 21indicates a slot in the edge of the top wall for a purpose to behereinafter disclosed.

The first sidewall 15 has a hole 43 for passage of the electric cord 14and a bearing hole 38 in which the shaft 27 is journaled. The bottomwall has a hole 19 for passage therethrough of the electric cord 14 andan opening 18 for passage of the supporting cable 41. The bottom wallalso has a slot 22 cut in its edge for a purpose to be disclosedhereinafter. A cable tube 25 is seated in the opening 18. A dependentthreaded canopy collar is positioned on the bottom wall over the twoholes 18 and 19 and around the tube 25.

Reference numeral 34 indicates a second side Wall having an end portionextending at a right angle thereto. A hearing hole 37 in the wall 34acts as a journal for the shaft 27. The second side wall 34 also hasears 35 and 36 positioned on its upper and lower edge respectively.

The second side Wallis mounted on the U-shaped housing member throughthe ears 35' and 36 which slidably engage the slots 21 and 22,respectively, of the top and bottom walls 17 and 16. When so mounted,the side wall 34 is parallel to the first side wall 15 and movabletoward or away from the wall 15 in the slots 21 and 22.

Reference numeral 27 indicates a drum shaft extended through andjournaled in the bearing holes 37 and 38 of the housing so assembled.The shaft 27 supports a cable drum 31 between the" first and second sidewalls 15 and 34 over the tube 25 in the bottom wall opening 18, as shownin Figures 2 and 3. When so positioned, the diametric hole 28 in theshaft 20 is positioned beyond the outer face of the second side wall 34and the threaded end 30 of the shaft is extended beyond the outer faceof the first side wall 15, as shown in Figure 2.

Reference numeral 26 indicates a ribbon or flat spring which is nestedwithin the drum 31 with one end anchored in a slot 29 in the shaft 27and the other end attached to the drum 31. The drum 31 is freelyrotatable upon the shaft 27. A cotter key 39 passesthrough the shaftbore 28 and is positioned against the outer face of the side Wall 34. Anut 40 engages the threaded end 30 of the shaft and bears against theouter face of the first side wall 15 when drawn up.

Reference numeral 41 indicates a flexible steel cable which is coiledaround the face of the drum 31 and attached at one end to the drum. Thecable passesthrough the tube 25 and has a fixture engaging element 42attached to its free end from which the fixture 12 is suspended. Theelectric cord 14 is coiled around the cable tube 25 and connected to theelectric fixture at its lower end. The upper end of the cord 14 passesthrough the bottom wall hole 19 and the side wall hole 43 into theelectric outlet box in the ceiling when it is connected to the electricsupply line. The canopy is slipped over the collar 23, hiding the reel10 from view, and is locked in place by means of locking element 24which engages the collar 23. as shown in Figure 1.

In adjusting the device originally, the cotter key is rotated therebyrotating the shaft 27 to load the spring to which the drum 31 isattached until the torque developed just balances the weight of thefixture 12. The key 39 is locked in place by passing its extreme endthrough the slot 21 and bending the end over so that the key can notrotate. The nut 40 is then drawn up upon the threaded end 30 of theshaft 27. This action draws the shaft through the first end wall bearing38. Since the cotter key 39 on the other end of the shaft 27 bearsagainst the outer face of the second side wall 34, the drawing up of thenut on the shaft 27 causes the second side wall to move in the slots 21and 22 toward the first side wall 15. In so moving, the second side wall34 compresses the drum 31 between it and the first side wall 15. As aresult of this compressive action, the edges 32 and 33 of the drum 31are brought into frictional engagement with their respective side walls34 and 15.

It will be noted that the cotter key 39 can be locked only in a positiongiving a minimum adjustment of one revolution of the shaft 27. Exactbalance is thus achieved by means of the adjusting nut 40 which drawsthe second side wall 34 against the edge 32 of the drum, as explainedhereinabove. The braking force of the walls 34- and 15 against the drumedges is calculated to prevent rotation of the spring loaded drum 31when the full weight of the fixture 12 is suspended from the end of thecable 41.

The additional spring torque created by pulling the fixture down is notsuflicient to overcome the braking drag created by the side walls 34 and15. As a result, the fixture will remain stationary in any position towhich it is lowered. However, if the fixture is lifted, as must be doneto raise it, the fixture weight may be reduced by three or four poundsmomentarily. This reduction of the pull on the cable 41 is sufiicientfor the torque of the coiled spring 26 to overcome the drag of the sidewalls 34 and 15 and the drum 31 is rotated easily, thus re-reeling thecable onto the drum 31. Release of the fixture restores the originalload and the rotation of the drum stops, holding the fixture at the newpoint. At the same time, raising of the fixture causes the coiled cord14 to contract to a taut new position. Thus both the cable 41 and thecord 14 are always neatly taut, there being no unsightly loops createdas a result of raising the fixture.

It will be noted that no pawls or other mechanical ratchet means areemployed in this device, so that the supported fixture can be movedsmoothly to the exact position wanted where it will remain upon releasewithout any minor upward or downward movement. Furthermore, it will beevident that the device just described is fabricated from simply shapedsheet metal elements that are inexpensive to form and easily assembled.

It will now be clear that there is provided a device which accomplishesthe objectives heretofore set forth. While the invention has beendisclosed in its preferred form, it is to be understood that thespecific embodiment thereof as described and illustrated herein is notto be considered in a limited sense as there may be other forms ormodifications of the invention which should also be construed to comewithin the scope of the appended claims.

I claim:

1. A tension reel for lighting fixtures, comprising in combination, asheet metal housing having a U-shaped member defining top, bottom andfirst side walls, the bottom wall having an opening therein and a slotcut in the edge thereof, the top wall also having a slot cut in the edgethereof, a second side wall member having slot engaging ears at the topand bottom edges thereof engageable with the slots in the top and bottomwalls, slidably mounted in said slots and movable therein toward or awayfrom the first side wall, a spring loaded drum rotatably mounted betweenthe first and second side walls over the bottom wall opening, a cablepassing through said bottom wall opening, attached to the drum andcoiled therearound, means on the free end of the cable for supporting alighting fixture therefrom, means for moving the second side wall memberin the U- shaped member slots toward the first side wall to compress thedrum therebetween, and means for adjusting the distance between thesecond and first side walls so that their frictional bearing against thedrum will hold the drum against rotation when a predetermined fixtureweight is suspended from the cable but will be incapable of holding thespring loaded drum against rotation when a greater or lesser weight isapplied to the cable.

2. A tension reel for lighting fixtures, comprising in combination, asheet metal housing having a U-shaped member defining top, bottom andfirst side Walls, the bottom wall having an opening therein and a slotcut in the edge thereof, the top wall also having a slot cut in the edgethereof, a second side wall member having slot engaging ears at the topand bottom edges thereof engageable with the slots in the top and bottomwalls, slidably mounted in said slots and movable therein toward or awayfrom the first side wall, a shaft extending between said side Walls andjournaled therein, said shaft having a diametric bore positioned beyondthe outer face of the second side wall, an axially extending slot, and athreaded end extending beyond the outer face of the first side wall, adrum mounted on the shaft having side edges faced toward and parallel tosaid side walls, a ribbon spring coiled around said shaft nested withinsaid drum and anchored at one end in the shaft slot and to the drum atthe other end, a cable attached to the face of the drum, coiledtherearound and extending through said bottom wall opening, means on thefree end of the cable for supporting a lighting fixture therefrom, a keymounted in the shaft bore, against the outer face of the second sidewall member, operable to rotate the shaft and attached spring to loadthe drum against rotation by a predetermined fixture weight suspendedfrom the cable, lock means for holding said shaft spring at the requiredtorque, an adjusting nut mounted on the threaded end of the shaft androtatable against the outer face of the first side Wall to draw theshaft key against the second side wall to move the second side wallinwardly of the top and bottom wall slots toward the first side wall,thereby causing the drum to be compressed at its side edges between theinner faces of the first and second side walls, the distance between thefirst and second side walls being adjusted so that their brakingpressure against the drum will counterbalance the increased torque ofthe spring due to the rotation of the drum caused by the unreeling ofthe cable brought about by the application of a force greater than thepredetermined one, thereby holding the drum against rotation in the newposition at all times; the side wall braking pressure being less thanthat required to overcome the spring torque acting to rotate the drumwhen the applied force is less than the predetermined one.

References Cited in the file of this patent UNITED STATES PATENTS492,808 Jenkins Mar. 7, 1893 1,374,459 Lichty Apr. 12, 1921 FOREIGNPATENTS 582,643 Germany Aug. 21, 1933

